Brian, sure looks like a proverbial needle in a haystack. Looks like the TS409-U uses a Channel Well Technology (CWT) PSM 200A-89. The QNAP part number is SP-5BAY-PSU. The only values I can find are:
Input:115-230V, 47-63 Hz, 3.0A
+5V 13A 65W max
+3.3V 17A 56W max
+12V 15A 180W max
-12V 0.3A 3.6W max
+5V 2A 10W max
Here are a few suppliers, depending on your region. Looks like it's popular in Europe (and expensive;) http://eng.estock.fr/basketadd.php?partnumber=SP-5BAY-PSU&eStockSID=83d633d87f10a3865c571508293582cf Here is the one from Qnap http://shop.qnap.com/index.php?route=product/product&product_id=72 The layout and a bit more data on the power supply from here http://www.cwt.com.tw/upfiles/layout01231293371.pdf Hope this helps, good luck.